Prof Dave Frame is Director of NZ Climate Change Research Institute at Victoria University in Wellington. He was a lead author on the 5th Assessment of the IPCC and is regularly published. He argues that from a mainstream policy perspective, climate change involves the provision of a global public good - a stable climate. He believes that climate modelling can provide inputs of fundamental importance for that task, by giving measures of the scale of the issue, and by highlighting aspects that matter the most.
His presentation focused on relative variability - that some parts of the world are experiencing much high variability in climate change than others - and that it is this variation which needs attention - that areas where greatest variation are being experienced require the greatest attention.
The reddest areas are those that are experiencing the greatest variation. I'm not including his mathematical slides here - but his method for measuring variation is important. You can see here that the tropics are the reddest - this is despite that fact - as he indicates - that places like Singapore might appear to experience quite low variations in temperature. However when you consider the previous mean and standard deviation of measures for those parts of the world - and consider how much these measures have changed - they are the areas where there has been the greatest variability. Variability being measured by the shift in standard deviations - in some cases which is greater than 3.
This slide introduced a new climate feature (new for me - despite being a physicist, my knowledge of atmpsopheric physics is woeful). And that is the Hadley Cell.A useful definition of this: a pattern of atmospheric circulation in which warm air rises near the equator, cools as it travels poleward at high altitude, sinks as cold air, and warms as it travels equatorward.... essentially it is a mechanism for the dispersal of heat energy. Air in the tropics gets hot, moves to cooler areas where it dissipates heat.
What I took from what Prof Frame said was that very high variability in tropical climate can be expected to have effects on adjacent areas - sub tropical and temperate areas such as Australia and New Zealand.
He used cyclone Debbie as an example of New Zealand's susceptibility to changes in tropical weather patterns. He argues that mitigation NOW (not just adaptation) will benefit the lives of people alive in the tropics NOW. (This is an important argument because much of the delay or lack of action around mitigation (reducing climate gas emissions) is based on the assumption it will take a very long time to have any effect on the global climate and conditions of life.)
This is an interesting depiction of options that might be open to society (societies) in response to climate change issues. Some actions/pathways will lead to greater future risks, others to greater future resilience.
This was the nub of his policy argument. He uses the Netherlands as an example of a society where most members of the population - accepting that they mostly live below sea-level - will accept taxes or charges that go toward protecting them against coastal innundation from the sea. He compares that with New Zealand - where, with obvious exceptions such as South Dunedin - because most people feel/believe they live sufficiently above sea level that they won't accept any taxes or charges that would only benefit those that are at risk of sea level change.
However, if New Zealanders - a huge number of whom were affected by Debbie, made the connection between that storm damage and the country's climate changing gas emissions, they might be prepared to act together, make some economic changes in their lifestyles, and begin to reverse a pattern of cyclones arising from a sharply varying tropical climate.
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